This invention relates to light sources and to lighting systems, and has a particularly advantageous application to the decorative illumination of structures and structural elements. The invention is especially effective when employed with LEDs as light sources, although it is emphasised that broader applications are encompassed.
British patent publication 2102933 discloses a lighting display configuration made up of multiple transparent polycarbonate or plastics tubes linked by socket units with several differently oriented recesses to seat the tubes. Each of the tubes contains an array of light bulbs, filament lamps or light emitting diodes (LED). The application illustrates a free standing framework of the tubes and linking socket units.
A known lighting product in strip form has a linear array of well-spaced LED chips in a close-fitting coloured plastics tube of rectangular cross-section. The tube is a little less than 1 cm in width and each LED chip is visible from the exterior both when not activated and as an individual point of light. The product is used to provide low light level safety lighting, eg., as a front edge xe2x80x9cnight lightxe2x80x9d marker for steps and stairways, and thus the rectangular tube is a protective carrier housing for the low light level LED marker lamps.
Another known product has small incandescent light bulbs embedded at intervals in an axial plane in a solid cylinder of plastics material. The bulbs are arranged as series sets in parallel, electrically connected across a pair of longitudinally extending wires also embedded in the cylinder. Each bulb stands out individually when the device is activated, so that the cylinder of plastics material effectively serves as a carrier forming a chain of spaced incandescent bulbs.
The present applicant has appreciated that a light tube structure in which multiple light emitting diodes are arranged within an elongated translucent tube, provides a wide variety of opportunities for novel strip lighting of structures such as playgrounds and the walls and roofs of commercial premises including restaurants. This opportunity is further enhanced by the recent availability of light emitting diodes of substantially enhanced luminance relative to conventional devices, and of multi-colour LED devices.
In one respects the invention is concerned with the decoration or highlighting of features of structures. In another respect, the invention provides for the fixing of translucent housings containing spaced LEDs on wall or frame surfaces of a wide variety of structures.
The invention provides a strip lighting device which includes:
an elongate housing that is at least partially translucent;
a multiplicity of light sources arranged at intervals within said housing; and
means to diffuse, disperse or scatter light from said light sources whereby on activation of the light sources, a visible optical effect is produced when the housing is viewed from the outside.
In a particular application, the invention is directed to a structure having one or more features highlighted or decorated by one or more of the above-described strip lighting devices.
Preferably, the highlighted or decorated feature of the structure is a corner or edge, for example an edge of a roof, a window or a door, or a corner between respective wall or roof sections. A particularly effective application is to a gable or ridge line of a building roof. The strip lighting device(s) may be mounted along the edge or corner, or adjacent to but offset from the edge or corner.
The housing of the strip lighting device may be substantially white, but is preferably a colour other than white. In one application of the invention, the structure is a commercial building and the color of the or each housing is chosen to match or complement the colour(s) of identification or trade mark signage displayed on the building.
The highlighted or decorated feature may alternatively be, e.g., a post, a rail or a border.
There may be mounting means that includes a mounting rail adapted to be fastened to said surface, and cooperable means on the strip and the housing for effecting a snap or sliding engagement of the housing to the strip so that the housing is generally parallel to, and preferably overlies, the strip.
The light sources are preferably light emitting diodes or other low voltage or semiconductor devices.
The invention further provides, in a third aspect, a housing assembly for strip lighting, including:
an elongate housing at least partly but preferably substantially wholly of a translucent material;
a mounting rail; and
co-operable longitudinally extending formations on the rail and the housing for effecting a snap or sliding engagement of the housing to the rail so that the housing is generally parallel to, and preferably overlies, the strip.
The snap or sliding engagement may be achieved between longitudinally extending rib means on one of the components, preferably the strip, and complementary groove moans on the other. There may be opposed longitudinal undercut formations in the groove means.
The strip conveniently includes a substantially planar rear engagement with the respective surface to which it is fastened.
Preferably, in all of the aforementioned as of the invention, the outer or front face of the elongate hollow housing is defined by a transversely domed or convex segment.
Preferably, in all the aforementioned aspects of the invention, the interior of the housing is provided with support means for one or more webs or strips extending longitudinally of the housing. One such web or strip may be a support web for the light sources and for the electrical connections to these light sources, and may thereby incorporate ribbon cable. A suitable support web is printed circuit board (PCB) laminate. The web or strip may be transversely oriented at any angle, eg. parallel to or normal to the backing surface, or otherwise. The light sources may be on either face or side of the support web or strip, or on both faces or sides.
Connector means is preferably provided to physically couple a pair of the elongate housings whereby the housings may be relatively longitudinally displaced in situ, eg. by thermal expansion or building subsidence, without being uncoupled. Where the light sources are provided on a plurality of support webs or strips having electrically conductive surface elements and extending longitudinally of the housings, connectors are preferably also provided for pairwise electrically and physically coupling the support webs or strips whereby the webs or strips may also be relatively longitudinally displaced in situ without being uncoupled, either physically or electrically. It is particularly advantageous to provide for such displacement both between housings and between support webs or strips carried by an array of the housings.
A further said strip or web may be an optical refractor or diffuser, arranged in front of or behind the light sources as appropriate.
In all aspects of the invention the housing may be hollow and/or may define a passageway in which the light sources are disposed. Alternatively, the housing may be substantially a solid, eg. moulding bout the pre-positioned light sources, or with cavities to receive the light sources.
Where the elongate housing is hollow, it is preferably a plastics (e.g. Polycarbonate) extrusion of substantially uniform cross-section, and is preferably translucent but not transparent. A translucent and also transparent housing may be preferred in some embodiments. The housing can be substantially rigid. A suitable form of the flexible tubular segment is a collapsible pleated web or concertina structure.
Presently, the base strip, flexible tube segments and coupling means are also at least partly provided in translucent material.
The means to diffuse, disperse or scatter may include e.g., a body portion of the housing, and/or light diffuser means in the passageway.
The invention, in a further aspect, provides a connector for physically coupling a pair of generally tubular components, including:
an integral moulded body which defines a pair of generally tubular portions slidably engageable with the respective said tubular components so that their interiors are in communication within the connector;
wherein said integral moulded body further defines a relatively thin wall portion between said generally tubular portions, said thin wall portion being resiliently deformable to compensate for relative variations in the relative positions of the generally tubular portions.
The material of the body is preferably silicone rubber or similar.
In a still further aspect of the invention, there is provided a connector for electrically and physically coupling a pair or more of support strips having electrically conductive surface elements including:
an integral moulded body with features which define spaced generally parallel channels or passages open at their outer ends to receive respective end fingers of the respective said strips, whereby the strips are aligned and generally co-planar;
electrically conductive contact mans in said channel or passages for engaging complementary contacts on said strips when said fingers are received in the channels or fingers;
means carried by said body electrically connecting each of the contact means for one strip carried by said body with one or more of the contact means for the other strip; and
resiliently deformable means on said body for latching said body to each of said strips.
Preferably, each of the electrically connecting means is provided contacts as an integral electrically conductive stripxe2x80x94more preferably, the strip is of appropriately conductive material, eg. phosphor-bronze or other alloy, mounted to be resiliently deflect by said fingers.
Preferably, the spaced channels are arranged along opposite sides of the integral moulded body, and open laterally from the body. In an embodiment, these channels are provided in elongate side portions linked by a central cross-piece in an I or H configuration.
The resiliently deformable latch means is preferably provided as a pair of deflectable tongue portions with lugs, which tongue portions is defined by slits in a web portion of the integral moulded body, e.g. bridging said elongate side portions of the body.
In still further aspects, the invention respectively provides (i) a strip lighting system including multiple strip lighting devices as described above, and (ii) a set of components for such a system including multiple such strip lighting devices, flexible tube segments, and suitable coupling means such as, eg., connectors according to the sixth and/or seventh aspects of the invention.